Exterminating apparatus



Feb.'20, 1940; B. F. FoRD 2,191,229

EXTERMINATING APPARATUS Filed oct. 11, 1957 INV ENTOR.

LBY Y M ATTORNEY.

Cil

Patented Feb. 20, 1940 f PATENT `.o1-rior N EXTERMINATING APPARATUS Benjamin F. Ford, Los Angeles, Calif., assigner to Eiectric Traps, Inc., Los Angeles, Calif., a corporation of California Application October 1l, 1937, SeriallNm168,324`

6 Claims.`

invention relates to apparatus for exterminating by the process of electrocution, rats and similar rodents or other animals.

It is the purpose of my invention to provide a rat extcrrninating apparatus which is characterized by being normally cie-energized to save current but energizable by the` bait-grabbing movements of a rat for a period only suicient to `electrocute the rat, `when the apparatus is automatically dre-energized and only re-energized by the bait grabbing movements of a succeeding rat.

It i a rat s also a purpose or my invention to provide exterminating apparatus as characterized `above wherein the relation of its parts is such that a rat, to reach the bait and the point oi electrocution, is compelled to climb a support so that OnCe gized,

electrocuted and the. apparatus cle-enerthe rat falls from and clear of the support make way for a succeeding rat.

exterminating carrying out my invention I provide a rat apparatus which embodies a electr ocuted.

In carrying out my invention I preferably provide a rat exterminating apparatus in which the transformer employed is of the constant current type so that should the control switch remain closed by failure of the rat to fall from the support, the current from the transformer secondary and through the rat as intermittently supplied by J the periodic opening' and closing of the thermostatic switch, will not rise in an amount suiiicient `to burn the rat and thus generate a lire, but will remain at a predetermined maximum sinlicient only to execute the rat.

With the above and other objects in view, the invention. consists the novel provision, construction, combination and interrelation of parts and features all as so disclosed and claimed.

I will describe only one form of rat exterminating apparatus embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawing:

Fig form l is a view showing in side elevation one of rat externnnating apparatus embodying my invention.

Fig. 2 is an enlarged vertical sectional view taken on the line 2 2 of Fig. l. p 3 is a View showing diagrammatically the ed of heavy wire screen for the dual purpose of giving electrical conductivity thereto and to facilitate climbing by a rat.

The upper end of the support il is spanned by al disk i9 otinsulating material secured in iixed position by rings 26 through which rivets 2l extend. This disk i9 is formed with a central opening 22 through which extends a contact arm 23. This arm 23 is in the form ofA a rod of such length as to extend above and below the disk, and it is supported in `upright position by a coiled spring 24 in` suchmanner that it is yieldably urged to this upright `or perpendicular position. The spring 2li surrounds the rod above the disk with one end secured to the arm and the other end secured to a binding vpost 25 extending through the disk i9. The` upper end of the arm 23 is pointed to receive and hold on the rod any suitable rat bait, downward movement of the bait on the arm being limited by a ring 25 held in fixed position on the arm by the upper end of the spring. i

A wire 2l is fixed at one end to the arm 23 and coiled about the same, the other end of the wire being looped and connected to a binding post 28 carried by the disk i9. The purpose of coiling and looping the wire is to allow the necessary lateral movement of the arm and` yet maintain an electrical connection between the arm and the binding post.

`Surrounding the arm 23 below the wire 2l is a second and relatively heavy contact wire 29. This wire 29 is coiled about but normally spaced from the arm 23 and it is supported in fixed position on `the lower end of a binding post St depending from the disk i9. In the position of the arm 23 as normally maintained by the spring 24 it is out oi Contact with the wire 29, but should the arm be moved laterally in any direction against the action of the spring 24, it will engage with the contact wire 25. Thus in effect the arm 23 and the contactwire 29 constitute a control switch S for` they form the terminals of a circuit, as will be described hereinafter.A i f,

As shown in Fig. 2, a transformer 'I is bolted to they base i5 within the conical support Il, and on this transformer is secured a bracket 3| carrying a disk 32 of insulating material. Secured to one face of this disk is a thermostatic switch of conventional form which comprises a metal bracket in which is secured-metal strips 34 having different coelicients of expansion. Around these strips is a sleeve 35 of insulating material, and wound on the sleeve is a heating coil 35. One end of the coil isvconnected to the bracket 33 While the other end is connected to a resistance coil 3l'. As bestshown in Fig. 3 the strips 3ftv normally contact with a setscrew exceeding a predetermined maximum.

38 mounted in a metal bracket 39 secured to the disk Also secured to the disk 32 is a relay 4D having an armature 4I normally spaced from a Contact 42 blut adapted to engage the latter when the relay is energized.

, The electrical connections between the various parts of the apparatus will be best understood from a consideration of Fig. 3. As here shown, the circuit for the relay 40 is in parallel with the circuit for the heating coil 35, and both circuits include a generator G or any other suitable source of alternating current. Also, the switch S is included in both circuits so as to control the closing and opening thereof. The circuit for the primary winding 44 of the transformer T embodies the armature 4i Therefore, this circuit is closedy only when the 'relay fit is energized. The circuit for the secondary Winding 43 of theA transformer is adapted to be closed only when the arm 23 and the support il are bridged by a rat in the act of grabbing the bait on the arm.

As will be clear from the diagrammatical showing in Figure 3, the transformer T is of the constant current type, that is, a transformer having a magnetic shunt with functions to prevent the current ilow in the secondary winding from In the present instance, this transformer is so designed that the maximum current flow in the secondary winding shallbe suflicient to electrocutev a rat but insuflicient to burn him.

' In the operation 'of the apparatus, a rat seeking Winding 155i.

the bait on the arm 23 climbs the Wire support il and in reaching for the bait, the rat not only electrically bridges the support and the arm, but moves the arm laterally to cause it to engage the contact 229. With closing of the switch S the circuit for the relay is completed to cause current from the generator G during any one alternation to flow through the wire 45, winding of relay 40, wire d5, bracket 33, strips 34, screw 38, bracket ,.39, wire Lil, contact arm 23, contact wire 29, and

wire #lil back to the generator.

Thus, the relay is energized to move the armature il into engagement with the contact 42, thereby completing the circuit for the primary Also, with closure of the switch S the circuit for the heating coil 35 is likewise completed, current flowing from wire 45 through resistance 3l, coil 36, bracket 33 and strips 34. The remainder of the circuit is readily traceable back to the other side of the generator through and the contact 42.'

ductively energized, thus causing current to flow from one side of the winding through wire 5l,

support Il, through the body of the rat, contact n arm 23, wire 24, and wire 52 back to the other side of the winding.

The voltage of the current induced in the secondary winding is sufficient to effect electrocution of the rat. If for any reason the rat after electrocution should fail to fall from the support I7 or to otherwise disrupt the circuit of the secondary Winding, current will cease to flow in this circuit by disrupting the circuit for the primary winding throughde-energization of the relay 40. This is effected by the heating f the thermostat to disrupt the connection between the strips 34 and the screw 38 thereby permitting the armature 4l to move out of engagement with the contact 42.

From the foregoing operation, it will be manifest that normally the apparatus is deenergized and that is is only energized to effect electrocution of a rat by the bait-grabbing movements of the rate to operate the switch S and simultaneously bridge the contact arm 23 and the support l'l, and that once electrocution of the rat has been effected the apparatus is automatically deenergized to eiTect cessation of the iiow of current therethrough. As the rat falls from the support after electrocution he is clear of the apparatus and hence does not interfere with the electrocution of other rats so that the apparatus is operable continuously to eiect the electrocution of rats. n

'Should a rat not fail from the support but remain in such position thereon as maintain the switch S closed, although the thermostatic switch will periodically disrupt the iiow of current through the rat, the transformer T by virtue of its constant current property will not permit the current flow to rise tol such a degree as to burn the rat, thus eliminating the possibility of fire.

In Figs. l and 2 I have shown the upper portion of the support Il' provided with a guard for the purpose of preventing accidental closing of the switch S and thereby eliminating the possibility oi' anyone being shocked as a result. This guard comprises a wire cage 53 fixed on the support il by one or more brackets 54. The bottom edge of the cage is reinforced by a ring 55, while the upper end of the cage is xed to and closed by a cap 56 in the center of which is secured an eye l which may serve as a handle for carrying the apparatus.

Although I have herein shown and described only one formof rat exterminating apparatus embodying my invention, it is to be understood that various changes and modifications may be made herein without departing from the spirit of my invention and the spirit and scope of the appended claims.

I claim:

l. An exterminating apparatus, comprising; a transformer; a normally open circuit including the secondary of the transformer; a supportof conducting material forming one terminal of said secondary circuit; a bait-carrying switch having a contact and an arm yieldably urged out of engagement with the contact and forming the other terminal of the secondary circuit, said switch being insulated from and mounted at an elevated point on the support; a normally open circuit for the primary of the transformer; a source oi alternating current in the primary circuit; a normally open second switch in the primary circuit; a control circuit including the current source, a relay for closing the second switch, and the bait-carrying switch, so that secondary circuit; a bait-carrying switch haV` ing a contact and an arm yieldably urged out of engagement with the contact and forming the other terminal of the secondary circuit, said switch being insulated from and mounted at an elevated point on the support; a normally open circuit for the primary of the transformer; a source of alternating current in the primary circuit; a normally open second switch in the primary circuit, a control circuit including the current source, a relay for closing the second switch, and the bait-carrying switch, so that when the bait-carrying switch is closed the relay is energized to close the primary circuit; and electro-responsive means for effecting cessation in current flow in the primary circuit a predetermined time after closure thereof to insure that the electrocuted rat will fall from the support.

3. In an electrocuting apparatus; a wire support of conducting material; a member of insulation on the upper end of the support; and a bait switch mounted on the member and comprising a contact arm, a contact, and means for supporting` the contact arm on the member so that the arm is urged out of engagement with the contact but can be moved into engagement with the contact by the bait-grabbing movements of an animal.

4. In an electrocuting apparatus; a substantially circular support of conducting material; a

substantially circular member of insulating material on the upper end of the support; and a bait switch mounted on the member and comprising a contact, and` a bait holding contact arm mounted for pivotal movement in any direction about a transverse axis to engage the contact under the bait grabbing movements of an animal; and means `for yieldably urging said arm to a position in which it is out of engagement with the contact.

5. An animal electrocuting apparatus, cornprising; a vertical support of conducting material adapted for climbing by an animal; a circuit closer subject to animal actuation and situated at the top of the support; a primary circuit including a source of` current, the primary of a transformer, a relay for controlling current flow `to said primary, a thermostatic switch for controlling current flow to the relay, said circuit closer controlling current ow to said relay and Y switch; and a secondary circuit including the support, the secondary of the transformer, and the circuit closer.

6. An animal electrocuting apparatus, comprising; a support of conducting material; a circuit closer mounted on and insulated from said support and subject to animal actuation; a primary circuit including a source of current, the 

